The earliest Laos legal document (and the earliest sociological evidence about the existence of the Lao people) is known as "the laws of Khun Borom" (also spelled "Khun Bulom"), still preserved in manuscript form.[1]
This set of memoriter laws is written in a type of indigenous blank verse, and reflects the state of proto-Lao society as early as the 9th century, possibly prior to their adoption of Theravada Buddhism, and prior to (or coeval with) their southward migration into the territory now comprising modern Laos (from North-Western Vietnam). good
While some Lao people regard Borom/Bulom as a subject of myth only[citation needed], Western scholars regard him as an historical figure, albeit there is very little factually known about him aside from the fact of his bare existence and the description of a very primitive kingdom in his laws.
In general terms, these ancient laws describe an agrarian society in which life revolves around subsistence agriculture with domesticated water-buffaloes (the gayal). The strict punishments set down for stealing or killing a neighbor's elephant reflect that these were (evidently) an expensive and important possession of the time.
The official History of Laos as introduced in government textbooks, is conventionally traced to the establishment of the kingdom of Lan Xang by Fa Ngum in 1353. This is a relatively conservative date to begin the history of the nation, providing a contrast to the course taken by Thai historiography (which reaches back implausibly far into proto-history). By the 14th century, when this "official history" begins, the speakers of early Lao-related languages had probably developed a reasonable base of population among the prior inhabitants of (what is now) Laos over the prior century or two.
The earlier inhabitation of the land by peoples such as the Mon kingdom of Dvaravati and Proto-Khmer peoples was given a great deal of emphasis in the histories of Laos written during the French colonial period. However, post-colonial historiography has instead sought to represent all peoples of Laos as equally "indigenous", relating the early history in terms of a complex interaction with the (admittedly more ancient) Cambodian kingdoms to the south, and praising the Proto-Khmer as Lao nationalists for their heroism and modern struggles against the French and Americans (see, e.g., the Ong Keo Rebellion starting circa 1902).
Both French colonial history and post-colonial (Communist) history sought to reverse the obvious racism of earlier, popular accounts that when the Lao migrated into the country, they simply conquered and enslaved the native inhabitants (viz., primarily Proto-Khmer people, described in such a context with the derogatory term "Kha-That"). This traditional view has almost no factual basis, but remains a commonly heard pseudo-history, and a special concern for teachers to address (or redress) in the classroom. Vatthana Pholsena provides a survey of the historiography on this point in Post-War Laos, 2006, Silkworm Books.
It is generally assumed that, as late as the 16th century, King Photisarath helped establish Theravada Buddhism as the predominant religion of the country. However, this aspect of official history may now have to change given recent archaeological discoveries in Cambodia and Vietnam, showing intact Pali inscriptions as early as the 9th century. (See: JPTS, Vol. XXIII, 1997: Peter Skilling, "New Paali Inscriptions from Southeast Asia")
While there can be no doubt that animism and fragments of Shiva-worship were popular in ancient Laos, evidence increasingly indicates a long, gradual process leading to the ascendancy of Buddhism (rather than a single king converting the country). The reverse also did occur, as with the historical layers of statuary and inscriptions at Wat Phu Champassak; the oldest are in Sanskrit, and worship Shiva, while the later evidence is Buddhist, subsequently reverting to animism (with the most recent statues simply depicting giant elephants and lizards, with no references to the organized religions of India, and neither Sanskrit nor Pali text).
It is significant to note that all of these official histories exclude the (possible and actual) influence of Chinese religion in the region. In fact, the ancient Lao calendar and Thai calendar are both of Chinese origin (adapted from the "Heavenly Stem Branch Calendar"), and do not reflect Indian cosmology. These calendars were both part of the royal religion (preserved in epigraphy) and, apparently, part of popular religion (fortune telling) for centuries.

Elections were held in 1955, and the first coalition government, led by Prince Souvanna Phouma, was formed in 1957. The coalition government collapsed in 1958 under pressure from the United States. In 1960 Captain Kong Le staged a coup when the cabinet was away at the royal capital of Luang Prabang and demanded reformation of a neutralist government. The second coalition government, once again led by Souvanna Phouma, was not successful in holding power. Rightist forces under General Phoumi Nosavan drove out the neutralist government from power later that same year.
A second Geneva conference, held in 1961-62, provided for the independence and neutrality of Laos, but the agreement was subverted by both the United States and North Vietnam and the war soon resumed. The government and army of Laos were generally neutral during the conflict. The United States and North Vietnam subverted the agreement by forming private proxy armies. Growing American and North Vietnamese military presence in the country increasingly drew Laos into the Second Indochina War (1954-1975). For nearly a decade, eastern Laos was subjected to the heaviest bombing in the history of warfare [1], as the U.S. sought to destroy the Ho Chi Minh Trail that passed through Laos. The country was also repeatedly invaded by Vietnam.
Shortly after the Paris Peace Accords led to the withdrawal of U.S. forces from Vietnam, a ceasefire between the Pathet Lao and the government led to a new coalition government. However, North Vietnam never really withdrew from Laos and the Pathet Lao remained little more than a proxy army for Vietnamese interests. After the fall of South Vietnam to communist forces in April 1975, the Pathet Lao with the backing of North Vietnam were able to take total power with little resistance. On December 2, 1975, the king was forced to abdicate his throne and the Lao People's Democratic Republic was established.

The new communist government led by Kaysone Phomvihane imposed centralized economic decision-making and incarcerated many members of the previous government and military in "re-education camps" which also included the Hmongs. While nominally independent, the communist government was for many years effectively little more than a puppet regime run from Vietnam. The government's policies prompted about 10 percent of the Lao population to leave the country. Laos depended heavily on Soviet aid channeled through Vietnam up until the Soviet collapse in 1991. In the 1990s the communist party gave up centralised management of the economy but still has a monopoly of political power.